Common childhood infections: Bacteria Flashcards
Name two bacteria that cause harm via their exotoxins [2]
Diphtheria: Corynebacterium diphtheriae
Cholera: Virbrio cholerae
Describe how Vibrio cholera causes diarrhoea by the exotoxin produced by the pathogen
Induces diarrhoea by:
- A-B toxin
- A part activates cell’s G-protein, modifies G-protein and keeps it in active state
- causes more and more production of adenylate cyclase: causes more cAMP
- this stimulates CFTR channel to have more Cl- leave cell: imbalance of electrolytes
- water follows Cl- and electrolytes
- causes severe d
Describe pathophysiology caused by Corynebacterium diphtheriae
- What process does the A-B subunit inhbit? [1]
- What are the pathological consequences for the heart [2] & nerves? [3]
- What structural change occurs in mouth? [1]
Diphtheria toxin: A and B subunits inhibits protein synthesis:
Heart implications:
- Myocarditis
- Heart block
Nerve implications:
- Difficulty swallowing
- Paralysis
- Diplopia
Get pseudomembrane in mouth
What are symptoms of infection of Corynebacterium diphtheriae infection [3]
Symptoms:
- Sore throat
- Fever
- Pseudomembrane (grey membrane at back of throat: obstructs resp. tract)
What are the three cocci gram +ve organsims need to know? [3]
Staphylococcus
Streptococcus
Enterococcus
Which part of the LPS membrane of bacteria is toxic? [1]
When is this released? [1]
Lipid A
Released during lysis of organsim
Meningococcal disease describes infections caused by the bacterium []
Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis
Which two molecules are activated by LPS that cause inflammatory cascade for meningococcal disease? [2]
IL-6
TNF-α
Describe the pathogenesis of meningococcal disease
What is the definiton of fever? [1]
How do the following differ from rectal temp [3]
- Ear
- Mouth
- Armpit
Temperature > 38oC
Ear: similar to rectal
Mouth: 0.5 lower than rectal
Armpit: 1 degree lower
Why do babies under 3 months get thoroughly teseted (blood tests, lumbar puncture, and x-rays) if have a fever? [2]
High suspicion of index because need to rule out sepsis and meningitis
Name three most common causes of septicaemia and meningitis [3]
Streptococcus pneumoniae
Neisseria meningitidis
* Group B and C
* Increase in Group W since 2009
* Teenagers, university students
Haemophilus influenzae B (HiB)
Why are young infants so vulnerable to infection? [1]
Young infants are not fully vaccinated – why they’re still vulnerable
Which vaccines are administered at 8 weeks old?
Diptheria, Tetanus, pertussis (whooping cough), polio, Haemiphilus influenzae type B & and Hep B
Meningococcoal group B
Rotavirus (gastroenteritis)
Which vaccines are administered at 12 weeks old?
Diptheria, Tetanus, pertussis (whooping cough), polio, Haemiphilus influenzae type B & and Hep B
Pneuomococcal
Rotavirus
Which vaccines are administered at 16 weeks old?
Diptheria, Tetanus, pertussis (whooping cough), polio, Haemiphilus influenzae type B & and Hep B
MenB
Which vaccines are administered at 1 year old? [6]
Haemophilus influenzae type B, MenC
Pneumococcal
MMR
Men B
What are the three cocci gram +ve organsims need to know? [3]
Staphylococcus
Streptococcus
Enterococcus
Which of the following causes “Pneumococcus”
Staphylococcus
Streptococcus
Enterococcus
Staphylococcus
Streptococcus
Enterococcus
What are the four bacilli gram +ve organsims need to know? [3]
Corynebacterium
Listeria
Bacillus: cereus (food pois); anthracis (anthrax)
Clostridium: tetani botulinum, difficile
Which of the following is anaerobic?
Bacillus
Listeria
Clostridium
Corynebacterium
Which of the following is anaerobic?
Bacillus
Listeria
Clostridium
Corynebacterium
Describe what would indicate on a gram stain that have a Streptococcus pneumoniae infection? [1]
Diplococci (come in pairs)
What are the three cocci gram +ve organsims need to know? [3]
Staphylococcus
Streptococcus
Enterococcus
Explain three immune defects that could predispose an individual to an pneuomococcal infection [3]
- HIV infection
- Hypogammaglobulinaemia (low levels of IgG due to B cells not being able to mature)
- Absent / non-functional spleen
Give three reasons for an absent / non-functional spleen [3]
Congenital asplenia
Traumatic removal
Hyposplenism (eg sickle cell)
Describe pathophysiology of pneuomococcal infection causing otitis media
Streptococcus pneumoniae first colonizes the mucosal surface of the human nasopharynx and can then infect the middle ear cavity via the Eustachian tubes
Eustachian tube is more horizontal in children
Easier to move from back of throat to middle ear
Presents as bulging tympanic membrane
If don’t treat then tympanic membrane will rupture and pus comes out ear
Name two rheumatological implications of pneuomococcal pneuomonia infection
Osteomyelitis (inflammation in a bone and bone marrow, usually caused by bacterial infection)
Septic arthritis
Name 4 invasive features of Streptococcus pneumoniae infection
- Meningitis
- Sepsis
- Osteomyelitis
- Septic arthritis
- Peritonitis
- Lobar pneumonia
- Empyema
Name the two most common presentations of Pneumococcal pneumonia [2]
- Lobar pneuomonia
- Empyema (a serious complication characterized by pus and bacteria in the pleural)
How would you manage empyema caused by pneuomococcal pneuomonia? [2]
Chest drain
Video-assisted thoracoscopic surgery (VATS)
Name the two vaccinations for Streptococcus pneumoniae [2] and how many serotypes they protect agaisnt [2]
Pneumococcal polysaccharide vaccine (PPV): Penuomax - covers 23 serotypes
Pneumococcal conjugate vaccine (PCV): Prevenar protects against 13 serotypes
Which pathogen causes A? [1]
Corynebacterium dipetheria
Which pathogen cauese this symptom? [1]
Neisseria meningitidis - septic patient
What is the most common cause of lobal pneumonia?
Streptococcus pneumoniae
